An atypical human rotavirus strain Z10262, isolated from a chronically
infected immunodeficient child, displayed an unusual genomic RNA elec
trophoretic pattern. Besides, Northern blot analysis indicated that th
is strain contained an abnormally migrating gene 11 equivalent. Sequen
cing of this gene showed that it was derived from a genetic rearrangem
ent which involved a partial duplication of the open reading frame (OR
F) encoding the non-structural protein NSP5. However, the duplicated r
egion contained a deletion and several point mutations relative to the
first copy of the ORF Phylogenetic analysis of human and animal NSP5
amino acid sequences including Z10262 revealed two groups of human pro
teins related to different animal proteins. The isolation and analysis
of Z10262 strain provides further evidence for the genetic complexity
of naturally occurring human rotaviruses.